Feeding attachment for sewing-machines.



R. K. HGHMANN. "SEEDING ATTACHMENT POR SEWING MACHINES.

APPLIGATION FILED OGT. 14, 1908.

Patented May 10, 1910.

FFIQ.

RICHARD K. HOHIVIANN, 0F SAN DIEGO, CALIFORNIA.

FEEDING ATTACHMENT FOR SEWING-MACHINES.

To all whom fit may concern: Y

Be it known that I, RICHARD K. Hoi-I- MANN, a citizen of the UnitedStates, and resident of San Diego, in the county of San Diego and Stateof California, have invented certain new and useful Improvements inFeeding Attachments for Sewing- Machines, of which the following is aspecilication.

This invention relates to the feed mechanism of sewing machines andparticularly to means for reversing the feed. Its objects are to providemechanism of simple construction which will reverse the feed of thecloth beneath the needle bar without shock or jan and without stoppingthe machine, which can be easily operated to effect this reversal andwhich can be easily attached to various types of machines now incommercial use embodying mechanism adapted to feed in only onedirection, whereby those machines will be rendered capable of reversingthe feed.

A further object is to provide a feed dog of such construction that itvis capable of feeding the cloth in either direction, and which at thesame time may be successfully used with a tucker.

To these ends my invention consists in mechanism which will reverse thedirection in which the feed dog moves when raised into contact with thecloth and in the form of the face of said feed dog containing teeth orprojections adapted to carry the cloth with the dog in whicheverdirection it moves. My reversing mechanism is an attachment which isdesigned to be secured to some of the ordinary sewing machines now incommercial use without changing or omitting parts of those machines, andwhich is simply interposed as a part of the chain of mechanism operatingthe feed dog. Two connected parts of the old feed mechanism aredisconnected from each other and are connected to my interposedreversing attachment.

The novel features of my mechanism and the advantages thereof will beapparent from the following description taken in connection with theaccompanying drawings.

In the drawinga-Figure l is a bottom plan view of my attachment togetherwith connecting mechanism for operating the feed dog. Fig. 2 is a sideview of my attachment and connected parts showing a portion of themachine table in section;

Specification of Letters Patent.

Application filed October 14, 1908.

Patented May IO, 1910. sel-iai No. 457,719.

Fig. 3 is a similar view omitting the feed dog and showing the table insection at a point nearer the attachment; Fig. l is a bottom plan viewof the attachment without the connected part; and Fig. is a perspectiveview of the feed dog.

In these drawings 1 represents the top of an ordinary sewing machine and2 represents the ordinary feed bar, partly broken away carrying the feeddog 3 at one end. It will be understood that in order to enable the feeddog to properly move the cloth forward beneath the needle bar it isnecessary for the feed dog to be in contact with the cloth when it makesits forward stroke and to be lowered out of contact when returning toits original position where it commences its forward stroke. In making acomplete stroke therefore the feed dog has four successive motions. Itis raised into contact with the cloth, moved forward the requireddistance for feeding, lowered out of contact with the cloth, and thenmoved back to the starting point. The means for giving these fourmotions are well known in the art.

In the drawings I have shown a cam 4L engaging a roller 5 on the feedarm 2 for raising and lowering the feed dog 3, in the slot 23 in thetable top and it will be understood that the cam groove is of such shapeand the rotation of cam 4: is so timed that the upward and downwardmotion take place at the end of the forward and backward strokes of thefeed arm. It is not necessary to show or describe this means forsecuring the upward and downward motion of the feed dog in detail sincethe means in common use may be employed and will be understood by thoseskilled in the art.

@ne means heretofore used for giving the feed arm 2 its backward andforward motion consists of a shaft 6 mounted to rock in fixed bearingsand having a fixed arm 7 pivotally connected at 8 to the end of the feedarm 2. This shaft- 6 is also provided with a liXed arm 9 which isordinarily secured by pivot pin l0 to the end of the reciprocating arm11 which passes through a slot 12 in the top plate l. This arm l1 isreciprocated by well known means which as above stated is properly timedwith the means for raising and lowering the feed dog. The reciprocationof arm ll rocks the shaft 6 and therefore gives to the feed arm 2 itsnecessary back and forward motion.

The parts so far described are well known in the art.

My invention resides in mechanism interposed bet-ween arms 9 and 11 forreversing the feed the arms 9 and 11 being disconnected from each otherand being connected to opposite ends of the interposed chain ofmechanism.

My attachment consists of a removable plate 13 adapted to be secured tothe under surface of the top 1 by screws passing through holes 14 and ofmechanism secured to the bottom of this plate 13. rlhe plate 13 has uponits under surface a curved arm 1.3 preferably formed integral therewith,and pivotally secured thereto at 16 is the bell crank lever 17 havingthe upwardly extending arm 1S. The longitudinal link arm 19 is pivotallysecured at one end to the arm 13 at 20 and at its other end is securedby the pivot pin 21 to the downwardly extend ing link arm 22. This linkarm 22 is secured at its lower end to the arm 9 by the pivot pin 10. The plate 13 is provided with a slot 12 through which passes thereciprocating arm 11 and this arm is pivotally connected at 24 to thebell crank lever 17.

1t will be observed that the above described construction makes acontinuous chain of connecting arms and links between the reciprocatingarm 11 and the feed arm 9., but thatthe links 19 and 22 form a looseelbow joint which will not serve to transmit motion unless restrained.1n order to prevent the free movement of the pivot joint 21 between arms19 and 22, and to thus make these arms transmit motion in the desireddirection I use a plate 25 adapted to slide alone` the under surface ofplate 13 by the side of and parallel with the arm 19 and make a-camgroove or slot QG in said plate in the form of an inverted V or heart,and. provide a roller 27 on the pivot 21 working in said groove or slot.The plate 9.5 slides in bearings formed by theI plates Q3, 29, whichhave openings fitting the reduced ends 30, 31 of the plate 25. rlheplate Q5 is normally held in the rearward position shown in Fig. 2 bythe coiled spring 32 which is secured at one end to the plate by pin 33and at its other end to the plate 13 by pin 34. In order to move theplate against the tension of the spring to its forward position shown inFig. 4 and to retain it in that position, l use a tumbler 35 engaging afinger 36 on the plate 25 and a latch 37 operated by a key 38 passingthrough an opening in' plate 13 and the table top 1. The tumbler 35 ispivoted at 39 and has a rounded socket engaging the end of finger 3G andalso has a curved offset or projection 40 which is adapted to ride up onthe projection 41 of the latch 37. It. will be understood that when thelatch 37 is turned the offset 40 will ride up on the projection untilthe projection reaches the position shown in Fig. 4 when the parts willbe locked, and it will be further understood that this rotation of thetumbler carries the finger 3G and its attached plate 25 to its forwardposition shown in Fig. 4. The shaft on which the latch. 37 is mounted ispreferably made hollow with a cross pin 42 therein and the key 3S ismade to fit in this hollow shaft and is provided with a vertical slot 43which embraces the cross pin 42, thus furnishing the connection by whichthe key turns the latch. The key is provided with a suitable handle 45above the table top for turning it.

1t will be observed that when the plate 25 is in its forward positionshown in Fig. 4 the roller 27 will at the beginning of its stroke be atthe lower rear point 46 of the slot Q6 and that at this time the arm 11is in its elevated position. A downward stroke of the arm 11 thereforemakes the roller ride up the slot to the apex thus raising link arm 22and drawing the feed arm 2 to the right in Fig. 1. On the other hand ifthe plate 25 is at its forward position at the beginning of the downwardstroke of arm 11 the roller 27 will be at the apex of the slot and thedownwz rd motion of arm 11 will force it to travel down to the point 47of the slot, thus moving the link arm 22 downward and moving the feedarm 2 to the left in Fig. 1. It will therefore be observed that adownward stroke of arm 11 will move the feed dog either to th-e right orto the left in accordance with the position of the reversing plate Itwill further be observed that the position of plate 25 can be changedinstantaneously while the machine is in operation without any binding orjars. rEhe roller 27 moves 'easily and freely along' the slot while thereversal is being effected just as it does in feeding in one directionand there is no more shock or jar than in ordinary feeding. It willfurther be observed that this reversal does not change the relativetiming of the vertical and longitudinal motions of the feed dog butmerely makes that dog travel forward in contact with the cloth in oneinstance and backward in contact with the cloth in the other instance.

The feed dog 3 is made of the form which is clearly shown in Fig. 5 ofthe drawings. it has upon its upper surface the longitudinal rows ofteeth 4S, 49, 50 and 51 separated from each other by longitudinalgrooves which extend below the roots of the teeth. The teeth upon rows4S and 50 face in one direction, whereas the teeth upon rows 49 and 51face in the opposite direction. It

will be observed that by this construction the rows 48 and 50 cooperateto feed the cloth when the dog is moving in contact therewith in onedirection, and that at this time the teeth in rows 49 and 51 do noteither help or hinder the feeding operation, since they face in adirection opposite to the feed. On the other hand when the dog is movingin contact with the cloth in the opposite direction the rows of teeth 49and 51 take hold of the cloth and serve to feed it. The teeth on any oneor each of the rows might be made to face in opposite directions, andWhile this would serve to feed the cloth in either direction, as abovedescribed, I have found that to use teeth on any one row facing inopposite directions will not produce satisfactory results in practice.When it is attempted to use such a feed dog with the ordinary tuckerwhich pushes the cloth in between the dog and the presser foot I findthat the points o-f the tucker will make contact with those teeth facingin a direction opposite to the feed and will consequently be broken orbent and the cloth will not be properly pushed by the tucker to form thetucks. With my form of feed dog this defect in operation is avoided,since the tucker may be so modiiied as to come in contact only withthose rows of teeth which face in the direction of feed. This may beeffected by removing the intermediate points on the tucker and it maythen be used with my reversing feed dog without coming in contact withteeth facing contrary to the direction of feed. I have found that fourrows of teeth give a uniform feed and entirely satisfactory results, butit is to be understood that I do not limit myself to this precisenumber.

Having thus described the invention, what is claimed is:

l. A reversing attachment for sewing machine feeds adapted to beinterposed in or removed from the driving mechanism comprising a trainof mechanism for transmitting motion the ends of said train beingadjacent each other, and adjustable means between the ends of said trainfor reversing the direction of the motion transmitted.

2. An attachment for sewing machines comprising a train of mechanism fortransmitting motion, a removable plate carrying said mechanism, the endsof said train being adjacent each other and the said train including anadjustable cam for reversing the direction of the motion transmitted.

3. A reversing attachment for sewing machine feeds adapted to beinterposed in the driving mechanism comprising two link arms pivotallysecured together, a roller secured to said arms at the pivot joint, acam having a V-shaped slot or groove in which said roller works, andmeans for moving said cam so as to bring said roller into either side ofsaid slot as desired.

l. A reversing attachment for sewing machine feeds adapted to beinterposed in the driving mechanism comprising two link arms pivotallysecured together, a roller secured to said arms at the pivot joint, alongitudinally movable plate by the side of said arms provided with aheart-shaped slot or groove in which said roller works, and means formoving said plate longitudinally and retaining it in its end positions.

5. A reversing attachment for sewing machine feeds adapted to beinterposed in the driving mechanism comprising two link arms pivotallysecured together at an angle, a bell crank lever connected to the end ofone of said arms and having a Xed pivotal support, roller secured tosaid link arms at the pivot joint, a longitudinally movable plate by theside of said link arms provided with a heart-shaped slot or groove inwhich said roller travels, and means for moving said platelongitudinally and retaining it in its end positions.

6. An attachment for ordinary sewing machines comprising a plate adaptedto be secured to the under surface of the top of the machine, a bellcrank lever adapted to be secured at one end to the ordinaryreciprocating arm for operating the feed, two link arms pivotallysecured together at one end, one of said arms being secured to the bellcrank lever and the other being adapted to be secured to a pivoted armfor reciprocating the feed dog of the machine, a roller at the pivotjoint of said link arms, a longitudinally movable plate provided with aheart-shaped slot or groove in which said roller works, and means formoving said plate longitudinally and retaining it in its end position.

7. In a sewing machine, the combination with a feed dog, ofdrivingmechanism therefor, a slidable plate having a cam groove forcontrolling the direction of feed without stopping the machine, a springfor normally holding said plate in position to feed in one direction,and a tumbler and latch for moving said plate into position to feed inthe opposite direction and for retaining it in position.

8. In a sewing machine, the combination witha feed dog, of drivingmechanism therefor, a slidable cam plate for controlling the directionof feed without stopping the ma chine, a spring for normally holdingsaid cam to feed in one direction, a shaftJ for moving said cam to feedin the opposite direction, and a key adapted to extend down through anopening in the top of the sewing machine to turn said shaft.

9. In a sewing machine, the combination with a feed dog, of mechanismfor moving said dog into and out of contact with the material beingoperated on, mechanism for reciprocating said dog longitudinally, and amovable cam having a heart-shaped groove engaging a portion of saidreciprocating mechanism for reversing the direction in which said feeddog moves.

l0. In a sewing machine, the combination with a feed dog having teethadapted to feed in either direction, of mechanism for operating said dogto feed the material being sewed, and means including a heart-shaped camgroove for reversing said mechanism.

l1. In a sewing machine, the combination with a feed dog having rows ofteeth extending in the direction of the line of feed, all of the teethin a row facing one end of said row, and the teeth of adjacent rowsfacing in opposite directions, of mechanism for operating said feed dogand for reversing the direction of its motion.

l2. A feed dog for sewing machines comprising teeth in longitudinal rowsextending in the direction of the line of feed some of which teeth facetoward one end of the row and some of which lface toward the other end,and all of the teeth in a single row facing in the same direction.

13. A feed dog for sewing machines, comprising longitudinal separatedrows of teeth extending in the direction of the line of feed some ofwhich teeth face toward one end of the row and some toward the otherend7 and all of the teeth in any single row facing in the samedirection.

14. A feed dog for sewing machines comprising four longitudinalseparated rows of teeth extending in the direction of the line of feed,the teeth on alternate rows facing opposite ends of the rows, and all ofthe teeth on a single longitudinal row facing in the same direction.

In testimony whereof I affix my signature in presence of two witnesses.

RICHARD K. HOHMANN.

`Witnesses W. IV. LAYMAN, ARTHUR L. BRYANT.

